Line switch and connections



April 22 1924. 1,491,154

F. A. LUNDQUIST LINE SWITCH AND CONNEGTINS Filed Oct. 23. 1918 lave/fof`terred to as motor 1.

Patented Apr. 22, 1924.

UNITED STATES FRANK. A. LUNDQUIST, OF

CHICAGO, ILLINOIS, AssIeNon, BY MnsNn AssIGNMnN'rs,

- T HENRY S. CONRAD, TRUSTEE.'

LINE SWITCH AND GONNECTINS.

Application led October 23, 1918.

To a-llwhom t may concern.'

Be it known that I, FRANK A. LUNDQUIs'r, a citizen of the United Statesof America, and a resident of Chicago, county of Cook, and State ofIllinois, have invented certain new and useful Improvements in LineSwitches and Connections, of which the following is a specification.

My invention relates to line switches and their' connections inautomatic telephone exchanges, and has for its object improvements insuch devices. :One object which may be mentioned as, a preliminary is anarrangement by which I dispense with the third wire normally usedbetween the connector and the subscribers switch. Another 0b ject whichI will mention in my preliminary statement is an arrangement by which Iuse the test magnet as a line relay.

The accompanying drawing is a diagram of a line switch and theconnections leading to and from the switch as far as such connectionsare necessary to an understanding of the present invention. y

In the center of the drawing is a tube 1 which slides on a standard 2when compressed air is admitted from pipe 3 to the interior of standard2. These partsconstitute a pneumatic motor which will be re- On the topof motor 1 are some insulated wipers which are designed to makeelectrical connections with stationary contacts when the motor 1 isoperated.

On one side of motor 1 are ratchet teeth Il adapted to be engaged by apawl 5 to stop the motor at any desired position. A magnet having coils6 and 7 acts upon its armature 8 to move pawl 5 into engagement withteeth 4. A spring 9 acts to move pawl 5 away from teeth 4.- and to movearmature 8 to its retracted position.

Adjacent tothe magnet (i4-T is a valve 10 to which compressed air flowsfrom a local supply pipe 11. The valve 10 is in the nature of a checkvalve which is normally held closed by the pressure of air in pipe l1.It has a st em12 which engages the armature 8 and acts to push saidarmature toward its retracted position. Back of armature 8 is a spring13 which acts to push the armature 8 toward its attracted position andto hold said armature in Contact with stem 12. The combined force' ofspring 9 and the air pressure on valve 10 is greater than the forceSerial No. 259,398.

of the spring 13, so that armature 8 is normally held in its retractedposition. But

when the magnet is energized, the attraction on .armature 8 plus theforce of spring 13 is greater than the combined force olf' spring 9 plusthe air pressure on valve 10, with the result that the valve is openedwhen the magnet is energized. When the valve 10 is opened, air flowsfrom pipe 11 to pipe 111 and thence to a motor 15 which is of the samecharacter as motor 1. yIn normal position, valve 10 permits air toexhaust from pipe 14.

At a convenient place is a magnet composed of coils 16 and 17 andarmature 18. A spring 19 presses armature 18 against the stem of valve20, but with a force less than enough to open said valve. But when themagnet 16-17 is energizechthe valve 20 is opened to permit compressedair to flow from pipe 11a to pipe 3. The pipe 11a is a branch of thesupply pipe 11.

Pivoted at 21 to the frame of the switch is a bell crank lever 22, onearm of which rests on motor 15y so that when said motor is operated saidarm is lifted to shift adjacentk contact springs. To the other arm oflever 22 is pivoted an arm 23 which vis pulledv upward hy a spring 241.W'hen motor 1 is in .normal position, a pin 25 on said motor engages thearm 23 to hold it in the posi# tion shown.

movement of lever 22 pushes arm 23 so as to shift the adjacentcontactsprings to the right. But if motor 15 operates after mo-, tor 1 hasope-rated, then spring 24 has pulled arm 23 upward so that the said armpasses `over the adjacent contactsprings without touching them.

In addition to the parts so far described there are batteries X and X',a generator G, another motor and valve with levers and If the motor 15operates when thelmotor 1 is in normal position, then the springs,certain contact springsand wipers a bridgeacross the contacts touched bythe l bushes 40, 41, and when the selector is seized by the line switchthe bridge is opened.

The consequent attraction oit the armature 8 throws the pawl 5 into theratchet 4 and stops the motor 1 with its wipers in engagement with thestationary contacts which represent the found selector.` The armature 8also opens valve 10 to admit air to motor 15, which motor tilts bellcrank 22 to shift springs 37 and 44 from previous position to contactwith springs 55 and 60. Motor also tilts bell crank 49 to open valve 50and permit compressed air to lcw from pipe 3 thru pipe 51 to motor 52.This motor shifts springs 29 and 32 so as to break the circuit formagnet 16-17 and to connect the station wires and 31 to the wipers 57and 62 as follows: 302953-54-3755- 56-57; and 3132-58-59-44-6U-61 62.y

When motor 15 moves lever 49 as before described, such movement ot 49permits spring 63 to turn lever 64 on its pivot so that the catch 65comes over the tail ot armature 18. As this occurs at the time, orslightly before, the circuit is broken thru magnet 16-17, the armature18 is retained in its attracted position and the valve 2O is held openso that air remains on motors 1 and 52. l

The parts remain in this condition while the subscriber at the localstation reached by wires 30 and 31 is talking to a called subscriber.When the calling subscriber hangs up his receiver he breaks the circuitfor magnet 6-7 and this permits motor 15 to fall back. rThis in turnshuts air from valve 50 and permits motor 52 to tall back. The Samemovement which permits valve 5() to close also turns arm 64 to releasecatch 65 from armature 18 so that said armature returns to normalposition.v This l-ets valve 2O close, whereupon motor 1 falls back tonormal position. y

When 15 first operated as previously described it was after motor 1 hadmoved. Consequently7 the tilting of bell crank 22 resulted in arm 23passing over the adjacent contact springs and into a position whichbrought the hook 66 on arm 23 behind a stationary block or catch 67.When motor 15 released as described, spring 37 acting on bell crank 22can return only part way to normal position until the i'all of motor 1causes pin 25 to release hook 66 'from catch 67. What happens is thatsprings 37 and 44 are suspended between the upper and lower contactswith which they normally engage but from which they are whollydisengaged during release operations.

From the line switch wires 68 and 69 lead to contacts on connectorswitches, and when some other subscriber calls the. subscriberassociated with this line switch he closes extensions of lines 68 and 69whereupon a circuit is completed as follows: Xw35-6- the callingsubscriber-69-72-73-597 48-X.

This actuates magnet 6 7 which throws pawl 5 into ratchet 4 so as toprevent motor 1 moving from normal position. The magnet valso opensvalve 10 so as to admit air to motor 15. This motor acts on bell crank22 and causes arm 23 to push the adjacent springs into engagement withother contacts, whereupon a current flows: generator G-74-75-76-77-78-29-30-local station -31-32--79-80-81--82--83--Gr- This isa signalling circuit which calls the subscriber at the local station whorcmoves his receiver and thereby closes a circuit thru the magnet 1617as in the previously described condition. The action of magnet 1617opens valve 2O and admits air to motor 1, and, thru previously openedvalve 50, to motor 52. Owing to the tact that pawl 5 had been previouslythrown into ratchet 4, motor 1 accomplishes nothing. But motor 52 shiftsthe adjacent contact -springs to cut ott generator G and connect wires30 and 31 to wires 68 and 69. These last may be traced as follows:30-29-53- 54-70-71-68; and 31-32-5859-73- 72(i9.

From the description which applies to the line switch as a callingswitch it will be seen that the magnet 6-7 becomes a line re` lay whichremains energized in a bridge across the talking circuit. Vhen the lineswitch is a called switch, the magnet 6-7 is the test magnet which isenergized over wires 68 and 69 leading back to a connector. lf the lineswitch is already acting as a calling switch, then the rise of motor 1lifts part 84 and the terminals of wires 68 and 69 are disconnected fromspring 7() and 73 so that a calling subscriber cannot find a busy lineswitch. But instead the wires 68 and 69 are switched to a pair ofsprings 85 and 86 which connect to a common buzz circuit (not shown)whereby the calling subscriber secures a busy signal.

When motor 52 operated to cut ott the generator G it also shifted theconnections of wires 30 and 31 from the magnet 16-17 18, the valve isstill held open and pressure is still on motorl. But when the circuit isbroken thru magnet 6-'-7, motor 15 will fallback and this turn willrelease armature 18and permit valve 2O to close. The arrangement hereinshown is such that the magnet 6-7 has its circuit closed thru both thecalling and called station when the call comes from some station other`than the one associated with the line switch. As-a consequence of this,the circuit for magnet 6 7 can be broke-n only when both subscribershang up their receivers at the end of a conversation. No specialappliances or attachments are needed for preventing the line switch frommaking a trunk hunting movement when the called subscriber is the lastto hang up. f

What I claim is: y e 1. In a line switch and connections therefor', amagnet serving as a line relay when the switch is a calling switch, andas a ring'-` ing relay when the switch is a called switch.

2. rIn a line switch and connections therefor, a magnet serving at onetime as a line relay and at another time as a magnet for holding theline switch at normal position, a signaling generator, means controlledby the magnet for connectingthe generator to the connections leadingfrom the line switch to the local station associated therewith, andmeansby which such connections for the generatoris interrupted when'said magnet acts as a line relay. y

3. A line switchhaving a pair of wires leading to aconnector switchand asecond pair of lwires leading to a local station, va signalinggenerator, means controlled over the irst pair of wires for connectingthe generator to the second pair, and means for subsequently connectingthe two pairs of wires to form a talkingcircuit;

4. A line switch having a pair of 1wires leading to a connector switchand a second pair of wires leading to a local station, a signalinggenerator, a pneumatic device for connecting the generator to the secondpair of wires so as to call the subscriber at the local station. amagnetfor controlling the operation of the pneumatic device, means forcontrolling they magnet by an impulse liiowing over the first pair ofwires, and

means by which the wires carrying such impulse are subsequently used ina talking circuit to the local station.

5. In a line switch and connections therefor, a line relay by which theline switch is controlled, and connections so arranged that upon acallcoming from a distant station to the station associated with theline switch said relay will have its circuit closed thru both thecalling and the called stations.

6.*A line switch having a pair of wires leading to a connector switchand a second pair of wires leading to a local station, a magnet arrangedto have` its circuit closed thru the first pair of Wires, and apneumatic device controlled by said magnet for connecting the twopairsof wires to form a talking circuit.

7, `A line switch having a ypair of wiresk leading to a connector switchand a second pair of wires leading to a local station, a.

magnet bridged upon the talking circuitr formed by connecting the twopairs of wires together, and a pneumatic device controlled by saidmagnet for controlling the completion of the circuit upon which it isbridged.

8. In a line switch and connections therefor, a magnet servingfirst as atest magnet and then as a line relay when the switch is a callingswitch, and first as a ringingjrelay and then as a line relay when theswitch is a called switch. y

9. A line switch having a pair of wires leading to a connector switchand a second pair of wires leading to a local station, a signallinggenerator, means controlled over the rst pair of wires for connectingthegenerator to the second pair,y and means for subsequentlydisconnecting said generators from said second pair of wires and :torsubsequently connecting the two pairs of wires to form a talkingcircuit. e

l0. A line switch having a pair of wires leading to a connector switchand a second pair of wires leading to a local station, a signallinggenerator means controlled over said first pair of wires for connectingsaidy generator to said second pair of wires to signal the subscriber atsaid local station, y

and a pneumatic device for subsequently connecting the two pairs ofwires to form a talking circuit.

1l. A line switch having a pair of wires leading to a connector switchand a second' pair of wires leading to a local station, aik

magnet on said line switch havingtwo windings, one of said windingsnormally connected'to one of said iirst pair of Wires and to one pole ofbattery, the other windf ing normally connected to the other wire ofsaid tirst pair of wires and to the other pole `or" battery, means foroperating said magnet over said first pair of wires, and means forconnecting said magnet to said second pair y oitwires.

l2. A Vline `switch having a pair of wires leading to a connector switchandasecond pair of wires leading to a local station, a

magnet normally connected to said first pair of wires, a relay normallyconnected to said second pair of wires, means operated in response tothe operation of said magnet when said switch is a calling switch fordisconnecting said relay from said second pair of wires, and said meansoperated in response to the operation of said relay when said switch isa called switch `for disconnecting said relaytrom said second pair ofwires.

13. A line switch having a pair of wires leading to a connectorlswitchand a second pair of wires leading to a localstation, a magnetnormally connected to saidrfirst pair of wires, a relay normallyconnected to said second pair of wires, means operated in response tothe operation of said magnet when said switch is a calling switch fordisconnecting said relay from said second pair of wires and Jforconnecting said magnet thereto, and said means operating in response tothe operation or" said relay when said switch is a called switch fordisconnecting said rer lay from said second pair of wires and forconnecting said magnet thereto.

14;. A line switch having apair of wires leading to a connector switchand a second pair oi' wires leading to a local station, a magnetnormally connected to said first pair of wires, a relay normallyconnected to said second pair of wires, ay pneumatic device operated inresponse to the operation of said magnet when said switch is a callingswitch for disconnecting said relay from said second pair of wires, andsaid device operated in response to the operation of said relay whensaid switch is a called switch for disconnecting said relay from saidsecond pair of wires.

15.' A line switch having a pair of wires leading to a connector switchand a second pair of wires leading to a local station, a magnet normallyconnected to said first pair ot wires, a relay normally connected tosaid second pair of wires, a pneumatic device in said switch fordisconnecting said relay from said second pair of wires and forconnecting both said pairs of wires together so that said magnet isconnected to both of said pairs, said device operated in response to theoperation of said magnet when said switch' is a calling switch, and saiddevice operated in response to the operation of said relay when saidswitch is a called switch.

16. A line switch having a pair of wires leading to a connector switchand a second pair of wires leading to a local station, a magnetnormallyv connected to said first pair of wires, a relay normallyconnected to said second pair of wires, a device in said switch fordisconnecting said relay from said second pair of wires and forconnecting both said pairs of wires together so that said magnet isconnected to both of said pairs,

said device operated in response to the op eration of said magnet whensaid switch is a calling switch, andsaid device operated in response tothev operation' of said relay when said switch is a called switch.

17. In a line switch a pneumatic device on said switch for disconnectinggenerator from the calledyline and for connecting the calling and calledlines together to form a talking circuit, a magnet and a relay on saidswitch, a source ofair pressure, said relay partially completing an airpassage from said source to said device and said magnet completing theair passage so as to cause the operation of said device when said switchis a calling switch, said magnet partially completing an air passagefrom said source to said device and said relay completing the airpassage so as to cause the operation of said device when said switch isa called switch.

18. In a line switch, a pneumatic device on said switch fordisconnecting generator from the called line and for connecting thecalling and called lines together to form a talking circuit, a magnetand a relay on said switch, a source of air pressure, 4said relaypartially completing an air passage from said source to said device andsaid magnet completing the air passage so as to cause the operation ofsaid device when said switch is a calling switch, said magnet partiallycompleting an air passage from said source to said device and said relaycompleting the air passage so as to cause the operation of said devicewhen said switch is a called switch, and means controlled by said magnetfor maintaining said device in operated position.

19. In a line switch, a pneumatic device on said switch fordisconnecting generator from the called line and for connecting thecalling and called lines together to form a talking circuit, a magnetand a relay on said switch, a source of air pressure, said relaypartially completing an air passage from saidsource to said device andsaid magnet completing the air passage so as to cause the operation ofsaid device when said switch is a calling switch, said magnet partiallycompleting an air passage from said source to said devi-ce and saidrelay completing the air passage so as to cause the operation of saiddevice when said switch is a called switch, and means by which eitherthe calling or called line controls the release of said magnet to causethe release of said device.

FRANK A. LUNDQUIST.

